Earlier quoted context omitted.
> What do you dislike about bugs being highlighted as you type many things "highlighted as you type" aren't "bugs". let greeting = "Hello " + user.name; Auto-fixing immediately flags this with "DAMN YOU USE A CONST!!!!" (multiple red squiggles that I have to hover and review). but... I might be making a change to it a few minutes later... but I've got some damn visual shit flashing in my eyes that "USE A CONST" conca…
The funniest part about that particular example is that it's highly likely you're using babel to support old browsers, and the compiled version just switches it back to string concatenation.
Again, an issue with switching between projects/styles, for me - one client/project insists on "const" in JS. Another client/project is supporting a product on IE9 for a client of theirs, but doesn't use any build tool for some of that JS, so we're not even supposed to use "let" or anything else "new" for some of that project. Mentally switching between those two worlds is like jumping between 2019 and 2009 every few days.
Realistically, could we introduce a transpiler? Technically yes, but operationally? It's a Frankenstein project that has so many larger issues that's low on the list for people (sections of the functionality are being migrated over to react altogether, and throwing 'more tools' in to the mix on legacy stuff is not desired).